Automatic clutch for drilling apparatus



Patented July 25, 1939 UNITED STATES AUTOMATIC CLUTCH FOR DRILLING'APPARATUS -Lloyd Yost.- Wilmette, Ill., laasignor to A. 0. 1 SmithCorporation, Milwaukee, Wis., a corporation of New York AppiieeuenNovember 1, 1937, serial Ne. 172,134

6 Claims.

'I'his invention relates to a clutch for use with drilling apparatuswherein it is desired to operate the drill bit by means not integrallyattached to the stem of the bit. In drilling deep wells, it is essentialthat such a clutch should be automatic because of the diiculty ofcontrolling the clutch from the top of the well.

The clutch is specifically adapted for use with hydraulic drills inwhich the drill pipe is norl0 mally maintained stationary or practicallyso with regard to the driving shaft on which the drilling bit ismounted. Frequently it is desirable to use the drill pipe as the drivingmea'ns and in this event a clutch is necessary to connect the drill pipeto the shaft carrying the drill bit.

It is an object of the present invention to provide an extremely simpleautomatic clutch for connecting the drill pipe to the drill shaft.

Another object of the invention is to utilize the mud or other fluidwhich is forced through the drill pipe as the force for holding theclutch out of engagement. V

'AI further object of the invention is to provide a clutch which willautomatically engage the drill 26 stem when the mud pressure is removed.

A still further object is to provide an improved bearing surface betweenthe clutch and drill shaft which insures long life to the mechanismandprevents the necessity of removing the drill from the 30 well andopening the outer shell to repair worn out parts. e

Reference is now made to the accompanying drawing which illustrates oneembodiment of the invention. In the drawing:

Figure 1 is a vertical vcentral section, parts being broken away,showing the relation of the clutch with respect to the other parts ofthe drilllng apparatus;

40 2-2 of Fig. 1 and'r Fig. 3 is a sectio Fig. 2; and

Fig. 4 is a vertical section taken along line 4 4 of Fig. 2. v

The drill pipe I extends from the top of the well to the housing 2 forthe hydraulic'turbine and serves as a conduit for the mud or other fluidcirculated while drilling. The drill pipe may be rotated by anyconventional means from the top of the well, but -as this invention isspecifically adapted for use with a hydraulic drill the major part ofthe drilling will be performed by4 the 'hydraulic motor disposed inhousing 2.

The hydraulic motor c'onsistslof a number of 65 turbine rotor blades I'moutedon a drill shaft resents the clutch in detail; taken along theline 3-,3 of

F18. 2 is a cro/ssection taken along the line- (Cl. Z-4) 3 and rotatingbetween stator blades 3" mounted on the housing 2 arranged Within thehousing. The fluid mud which is pumped through the system acts upon theblades to rotate the shaft and drive the drill bit 3". Any suitableconnection 5 between the stem of the bit and the drill shaft 3 may beemployed.

The wall of the housing or drill shell is provided wlth an elongatedrecess or pocket 4 which contains a ball 5, for engaging the drillshaft. 10 For convenience the pocket may be fabricated in a separatepiece which is 'welded or otherwise secured in the body of the shell. Inthe drawing two such pockets are illustrated, arranged onopposite sidesof the drm shaft, but any number, l5 one or more, may be employed.

Each pocket recedes from the center of the drill shaft 3 in order thatthe ball, whengat the outer extremity of the pocket may be completelyremoved from contact with any'point on the sur 20 face of the shaft. Atthe outer end of the pocket there is a port 6 through the housing,having its axis approximately radial to the center of the ,sphericallyshaped contour of the end of the pocket and Aforming therein a valveseat for the 25 ball. At theinner end of the pocket there is an abutment1 for holding the ball 5 in clutching engagement as shown.

Each recess 4 is inclined at` aslight angle, as shown in Fig. 3'with theend having the port l 30 slightly elevated with respect to the other endof the recess. Accordingly the ball 5 will normally roll to the lowerend of the recess into engagement with the drill shaft unless held tothe upper ed of the recess by an internal pres- 35 sure.

For each clutch, the drill shaft itself is provided with an abutment 8,-in the shape of a spherical socket for contact with the ball when theclutch is in operation. A tapered surface 9 on the shaft 40 merging fromthev base of the abutment 8 gradually forces the ball into the recess 4when the drill shaft is rotated ahead of the housing.'

With the ball in the position shown` on the drawing, if the outer shellbe rotated in the di- 45 rection of the arrow shownthereon there will bea clutching or driving action between it and the drill shaft. This is adirect pressure with the ball acting as a strut between the drivingabutment 1 and the driven abutment l. The 50 pressure is distributedover a considerable area of the surfaces of the shell and shaft as botho! the abutments 1 and 8 are spherical sockets complementary to theball. In this respect the invention crnstitutes a decided improvementover the 55 [ordinary rolling clutch which operates by pinching actionwith a highly concentrated pressure'on space between the shaft and theshell is under pressure greater than that outside of the shell in the,well, and due to the port 6 the ball 5 is forced onto the seat formed bysaid port and held at the end of the pocket. As long as the drill shaftis operated by the turbine the clutch will remain out of contact withthe shaft.

If and when it is desirable to drive the drill shaft by mechanicalpower, as by the drill pipe leading to the top of the well, the flow ofmud is reduced or entirely stopped and each ball automatically rollsinto engagement between the two principal members. In this manner, theclutch becomes'engaged whenthe drill shell is driven ahead of the ydrillshaft, andv disengages when the shaft rotates ahead of the shell.

The invention having been described, what is claimed is:

1. In a wellvdrilling apparatus, a drill pipe, a

drill bitrotatably attached at the lower end thereof, a clutch forconnecting said drill pipe to said drill bit, and fluid pressure meansresponsive to the ow of drilling fluid through the apparatus for holdingsaid clutch member in disengagement.

2. In apparatus of the class described, a driving member, 'a drivenmember, and means for controlling a clutch member therebetween,comprising a pocket in one of said members for receiving the clutchmember, said pocket having an opening at one end thereof and fluidpressure means for holding said clutch member against said opening whendisengaged.

3. In a well drilling apparatus in which the drill shaft is vnormallydriven by a hydraulic motor actuated by drilling iluid forced throughthe apparatus, means for actuating the drill shaft by a drill pipeleadingyto the top of the well, such drill bit, a clutch memberconnecting said shell to said shaft, a pocket disposed within the drillshell for retaining said clutch member, the walls of said pocketengaging said clutch member to hold the lsame in clutching engagementwhen said clutch member is at one end of said pocket, and meansresponsive to the flow of drilling fluid through said motor for holdingsaid clutch member' in disengagement when the clutch member is at theother end of said pocket.

5. In a well drilling apparatua; the combination of a drill pipe, adrill shell at the lower end thereof, a drill shaft rotatable Withinsaiddrill shell and carrying a drill bit, and a clutch member connectingsaid drill shell to said drill shaft, said drill shell having a pocketinclined to the horizontal for carrying said clutch member intoengagement with said shaft, and said shaft having on its periphery anabutment to engage said clutch member when said drill shell drives saidshaft, and having its surface from the base of the abutment taperedoutwardly to Aforce said clutch member into said pocket and out ofengagement with said shaft when said shaft is rotated ahead of saidshell. v

6. In a hwell drilling apparatus, the combination of a drill pipe, adrill shell at the lower end thereof, a drill shaft rotatable withinsaid drill shell and carrying a drill bit, a substantially sphericalclutch member disposed between said drill, shell' and saiddrill shaft, apocket in 'said drill shell for 'receiving said clutch member and beingof varying depth for forcing said member against said drill shaft fordriving the-same, an abutment on said shaft for engaging said clutchmember when in driving position, and iluid pressure means for holdlingsaid member in the deeper portion of said pocket when the same isdisengaged from the drill shaft.

. LLOYD YOST.

